Omega - The Professor: Missing Assistant

When you head into the Quarantine Zone at Omega, you'll do so in order to reach Dr. Mordin Solus, a brilliant Salarian doctor and scientist. When you finally meet him at his makeshift clinic, he'll give you a cure that will help those who are sick and infected, and as an aside, he'll mention his missing lab assistant, a human male by the name of Daniel. If you want to, you can offer to help the doctor find Daniel, who went out into the Quarantine Zone, and hasn't been heard from since. Doing so will unlock this side quest, which isn't only easy to complete, but will be completed in about ten minutes in-game time from the moment you undertake the quest.

After speaking with the doctor, receiving the cure, and learning about Daniel, you can head out into a yet-unsearched part of the Quarantine Zone. You'll have a heated battle in a wide open room with myriad Blood Pack Troopers almost immediately after leaving the clinic. Following that battle, you'll have to walk up some stairs and head leftward down another pathway. This will allow you to reach a room with two doors leading out of it, one on the left and one on the right. The door on the right allows you to continue with your main quest, so for the time being, ignore it. Instead, head through the door on the left. Here, you'll witness a brief cutscene with Daniel, who is being held hostage by gun-toting Batarians. Paragons can quickly diffuse the situation and see to it that Daniel is released unharmed, though riding on the neutral or Renegade path may result in completely different actions. Nonetheless, once Daniel is freed (or whatever happens to him otherwise), this quick, easy and brief side quest will conclude.